It might just pay to see if you can find some information electrolysis of dissimilar metals, although your coolant should take care of it some motors were specific about what coolant they ran due to different materials in the head to the block, welsh plugs, radiators, heaters and the like. Early commodore v6s you had to use holden v6 coolant, they were known as aspros, early wasser boxers you had to use VW coolant they were known as aspros and I'm sure there were a lot more, maybe your sacrificial anode will take care of it (thermostat housing) although that didn't work for commodore or VW, I don't know it's all supposition on my part, I'm not trying to scare you just warn you.

Do not bond the pipe to the engine you will basically creating a battery and then you will get electrolysis of dissimilar metals